Apparatus for feeding articles



March 15, 1966 P. M. GRUNWALD 3,240,332

APPARATUS FOR FEEDING ARTICLES Filed June 4, 1963 8 Sheets-Sheet 2 March 15, 1966 Filed June 4, 1963 P. M. GRUNWALD 3,240,332

APPARATUS FOR FEEDING ARTICLES l 8 Sheets-Sheet I5 March 15, 1966 P. M. GRUNWALD 3,240,332

APPARATUS FOR FEEDING' ARTICLES Filed June 4, 1965 8 Sheets-Sheet 5 P. M. GRUNWALD APPARATUS FOR FEEDING ARTICLES March 15, 1966 8 Sheets-Sheet 6 Filed June 4, 1963 March 15, 1966 P. M. GRUNWALD APPARATUS FOR FEEDING ARTICLES 8 Sheets-Sheet 7 Filed June 4, 1963 KQ @wml mm FEU, n.05,

March 15, 1966 P. M. GRUNWALD APPARATUS FOR FEEDING ARTICLES 8 Sheets-Sheet 8 Filed June 4, 1963 NGN United States Patent O 3,240,332 APPARATUS FOR FEEDING ARTICLES Peter M. Grunwald, Zurich, Switzerland, assigner to kWestern Electric Company, Incorporated, New York, N.Y., a corporation of New Yorlr Filed June 4, 1963, Ser. No. 285,438 12 Claims. (Cl. 209-75) This invention relates to apparatus for feeding articles and, more particularly, to apparatus for feeding and orienting articles having surfaces of differing characteristics.

In the mass production of many articles, the articles are processed through several areas, a particular operation or series of operations being performed at each area. For example, in the mas-s production of transistors, a slice of semiconductor material having a plurality of pairs of rectangular, metallic contacts or stripes disposed thereon is diced to form a plurality of minute wafers, each wafer -being a square approximately 30 mils x 30 mils with a thickness of 4 mils and having a pair of contacts o-n one of its surfaces. The wafers are then bonded to individual headers having a pair of postlike terminals, after which individual leads are bonded to each contact and to a corresponding header post. In order to facilitate the lead bonding operation, it is desirable that each Wafer be bonded to its header in a manner such that each of its contacts is in a predetermined relationship to its corresponding terminal. Accordingly, this necessitates that each Wafer be presented to the wafer bonding area in a predetermined orientation.

Heretofore, such orientation has been accomplished manually, the operator selecting a wafer from a bulk supply of randomly arranged wafers, positioning it to a desired orientation and then depositing it into a magazine or carrier. Obviously, performing these steps on a fully manual basis is time consuming and not compatible with m-ass production techniques. Accordingly, there is a need for mechanized apparatus Whichy will select wafers from a bulk supply, feed them to an orienting station and discharge the oriented wafers into a magazine or, if desired, directly to another machine for subsequent operation thereon.

It is an object o-f this invention to provide new and improved apparatus for feeding articles.

It is another object of this invention to provide new and improved apparatus for feeding and orienting articles having surfaces of differing characteristics.

It is a further object of this invention to provide new and improved apparatus for feeding and orienting articles having surfaces of different light reflectivity characteristics.

It is still another object of this invention to provvide new and improved apparatus for feeding and orienting minute articles, such as semiconductor wafers, having a surface marking.

It is a still further object of this invention to collocate initially randomly arranged articles into a `single row of substantially dimensionally correct articles.

Apparatus for feeding and orienting articles having surfaces of diifering characteristics illu-strating certain features of the invention may include means for receiving such articles, arranging them seriatim, and advancing the seriatim arranged articles along a predetermined path of travel to sensing means. The sensing means inspects a surface of the articles exposed thereto and senses a characteristic of the surface. Means responsive to the sensing means are provided for distinguishing surfaces of a first type characteristic from those of a second type ch-aracteristic and for ejecting from the series of advancing articles each of the articles which has been ICC presented to the sensing means with a surface of the second type characteristic exposed for inspection. Accordingly, each of the remaining articles of the advancing series has the surface thereof with the first type char-acteristic facing in a common direction. Means disposed in the path of travel of the remaining articles are provided for selectively engaging and rotating an individual article to position the article in a desired -angular orientation in the plane of the surface of the first type characteristic.

In one illustrative embodiment of the invention the articles are wafer-like and are received by and advanced along a track having an inclined sidewall and an adjoining base projecting laterally from the bottom of the sidewall. The width of the base along a rst section thereof is wide relative to the thickness of a single article and the articles are advanced 'along this section in a random arrangement; that is, some articles may travel edgewise with a surface thereof contacting the sidewall; other articles may travel with -a surface thereof contacting the base; and still others may travel atop or alongside other articles. In order to collocate the articles seriatim, the width of the base along a second segment thereof is narrowed so as to support only a single article, thereby precluding an article from traveling with one of its surfaces superimposed on the surface of another. The sidewall, along a section thereof commensurate with or subsequent to the narrowing of the base, has a slant height sufficient to support only a `single article, thereby precluding an article from traveling with one of its edges supported upon an edge of another article. In this manner, the articles are formed into a single row for presentation to the sensing means.

According to one aspect of the invention, where the difference in surface characteristics includes a difference in surface light reffectivity, the sensing means includes a light source and a photoelectric device arranged with respect to the track such that as an article is advanced into registration with the light source and an opening provided in the track sidewall, light is reflected from the article and directed to the photoelectric device. The photoelectric device is connected to a circuit which is functional upon an article being presented to the sensing means with a surface of one type reflectivity in facing relationship thereto, to cause a `stream of fluid to `be passed through the sidewall opening to eject the article from the track.

According to another aspect of the invention the eng-aging and rotating means include a rotatable member selectively movable into engagement with an article to be oriented. Selective rotary motion is imparted to the member by connecting it to a motor having means associated therewith for controlling the motion thereof in -accordance with a desired angular orientation of the article. To this end the controlling means is provided with a plurality of selectively actuable time delay circuits, the time delay of each circuit corresponding to the time required for the motor to rotate through a particular angle.

Other objects and advantages of the invention will be more readily understood from the following detailed description when considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a fragmentary, perspective view of article feeding and orienting apparatus embodying certain principles of the invention with portions thereof broken away and removed for purposes of clarity;

FIG. 2 is a fragmentary front elevation view of the apparatus of FIG. 1 wit-h portions thereof removed for purposes of clarity;

FIG. 3 is an enlarged, perspective View of a semiconductor wafer which may be fed and oriented with the apparatus of FIG. 1;

FIG. 4 is an enlarged, fragmentary, perspective view taken along the line 4-4 of FIG. 2 with parts thereof broken away and removed for purposes of clarity;

FIG. 5 is an enlarged, fragmentary, perspective view taken along the line 5-5 of FIG. 2 with parts thereof broken away and removed for purposes of clarity;

FIG. 6 is a schematic diagram of a photoelectric circuit for testing the surface characteristics of articles;

FIG. 7 is a schematic diagram of an article accumulation control circuit;

FIG. 8 is an enlarged, fragmentary, perspective view taken along the line 8-8 of FIG. 2 of an orienting station according to the invention with parts thereof broken away and removed for purposes of clarity;

FIG. 9 is an enlarged, fragmentary, perspective view taken along the line 9--9 of FIG. 2 of an orientor according to the invention with parts thereof broken away and removed for purposes of clarity;

FIG. 10 is an enlarged, plan view illustrating the possible orientations an article, such as a semiconductor wafer, can occupy in a channel forming a part of the feeding and orienting apparatus;

FIG. 11 is a schematic diagram of a photoelectric circuit for determining when a magazine used with the feeding and orienting apparatus is fully loaded;

FIGS. 12 and 13, combined, constitute a schematic diagram of an electrical control circuit embodying certain principles of the invention;

FIG. 14 is a diagrammatic view showing how FIGS. 12 and 13 are arranged to complete the electrical circuit.

Referring now to the drawings, there is shown in FIG. 1 an apparatus for feeding and orienting articles having surfaces of differing characteristics, such as semiconductor wafers -20, which includes a circular vibratory feeder, ldesignated generally by the numeral 21, and a linear vibratory track, designated generally by the nuv which is provided with an integrally formed mesa 24.`

having a base contact 26 and an emitter contact 27 alloyed to the top surface thereof. Additionally, as a result of the manufacturing process, the top surface of the wafer, i.e., the surface containing the emitter and base contacts, is polished and hence, is of a higher reflectivity than the bottom surface.

The circular feeder 21 is of the conventional type, and includes a vertical bowl 28 having a horizontally extending dish-shaped loading portion 29 secured to its lower extremity for receiving the wafers 20-20, the dish extending underneath the initial portion of the linear track 22 for reasons which will become readily apparent from the discussion which follows. The bowl 28 is constructed with a spirally inclined track 31 around its outer periphery, which communicates with the loading dish 29 at its lower end and an exit chute 32 at its upper end. Provided with the bowl 28 is a base unit 30 (FIG. 2) which contains an electromagnetic drive for imparting vibrations to the bowl in a manner which causes the wafers 20-20 to move radially inwardly of the bowl and in a circular path along its outer periphery. Thus, when the drive unit is actuated, the wafers 20--20 deposited on the loading dish 29 move radially inwardly of the bowl and up the spiral track 31 to the exit chute 32, whereupon they fall onto the linear track 22.

As seen in FIG. 2 the linear track 22 is supported for vibratory movement by a pair of angularly disposed, tuned springs 33-33 connected at their upper ends to the track 22 and at their lower ends to a support member 34. Vibratory motion is imparted to the track in a conventional manner by an electromagnet 36, mounted on the support member 34, coacting with an armature 37 projecting from the underside of track 22. Upon energization of the electromagnet 36, a downward force is exerted on the armature 37 which causes the springs 33-33 to ex and move the track 22 downward in an inclined arcuate path. De-energization of the electromagnet 36 allows the springs 33-33 to return the track to its normal position. As a result of the vibratory motion imparted to the track 22, linear movement from left to right, as viewed in FIG. l, is imparted to the wafers 20-20 thereon. Optimum feeding of the wafers 20-20 along the track 22 is accomplished by tuning the springs 33-33 to vibrate the track at a frequency substantially equal to the frequency of the electromagnet energizing means, in the present instance, 60 cycles. The distance advanced by each wafer 20 during each cycle is a function of the mass of the wafer and the amplitude of the vibratory motion imparte-d to the track 22.

As best seen in FIG. 4 the entrance end portion of the track 22 is of a generally V-shaped cross-section and includes a wide inner sidewall 38 inclined at a preferred angle of approximately 45 with the horizontal and having a narrow base 39 extending orthogonally therefrom. The width of the base 39 along a iirst segment 39a, located beneath the chute 32, is large relative t0 the size of a wafer 20 to facilitate the reception of wafers from the chute 32 onto the track 22. As the wafers 20-20 fall from the chute 32, some land and remain on the segment 39a, while others land thereon and drop off as a result of their momentum. These latter wafers are directed to the loading dish 29 by a guide member (not shown) and are subsequently re-fed to the track 22.

The wafers are advanced along the segment 39a in a random arrangement. For example, some wafers, such as wafers 20a, may travel with one of their surfaces contacting the segment 39a; others, such as wafers 20h, may travel edgewise With a surface contacting the sidewall 38, and still others may travel atop or alongside other wafers, such as wafers 20c and 20d respectively. In order to collocate the wafers 20-20 into a single row, the width of the base 39 along a second segment 39h is narrowed so as to accommodate only wafers traveling with one of their surfaces contacting the sidewall 38, that is, the width of the second segment 39b is equal to the thickness of a single wafer. As a result, those wafers traveling along the segment 39a which do not have a surface contacting the sidewall 38 (such as wafers 20a and 20d), fall off the base 39 onto the loading dish 29 when they reach the segment 39b. The wafers 20h and 20c, because they have their surfaces contacting the sidewall 38, remain on the base 39 during `their travel along the segment 39b.

In o-rder to remove the overlying wafers 20c from the track 22 and thereby form a single row of wafers 206, an opening 40 is provided in the sidewall 38, which is larger than a single wafer 20 and is located at a distance from the base which is approximately equal to a peripheral dimension of the wafer. Thus, the wafers 20c as they reach opening 40, fall therethrough and down a passageway 42 communicating therewith. Upon exiting from the passageway 42, the wafers fall by gravity onto the loading dish 29.

The wafers 20-20,'after being formed into a single row, are screened to eliminate oversize and undersize wafers, as wel] as Wafer chips, particles and the like which might interfere with proper operation of the apparatus. Oversize wafers 24T-20, that is, wafers that are larger than a desired size, in this instance 30 x 30 mils, are eliminated by a nitrogen stream which is introduced into the track 22 from a conventional source (not shown) through an opening 43 located in the sidewall 38, the opening being located at a distance from the base 39l which is slightly greater than the upper tolerance limitl of the peripheral dimension of a wafer 20. Thus, wafers Ztl-20 which are equal to, or less than the desired size pass under the nitrogen stream, while those which are,

larger than the desired size, are contacted by the stream and are blown from the track 22. Undersize wafers, as well as chips and particles, are eliminated by an opening 44 in the sidewall 38 of the track 22 which extends upwardly from the base 39 and is smaller heightwise than the desired wafer size. The height of the opening is increased at its end 46 in order to accommodate chips and particles which have a dimension equal to, or greater than, either peripheral dimension of a wafer 20. The width of this enlarged opening is smaller than either peripheral dimension of a wafer 20 to preclude good wafers from falling therein. The wafers or chips which fall into opening 44 drop down a chute 46 and into a reject receptacle (not shown) located adjacent to the track.

After screening, the wafers are advanced to a surface testing station, designated generally by the reference numeral 47 (FIG. 5), Whereat those wafers which are advanced with their top surface, i.e., the surface containing the contacts 26 and 27, contacting the sidewall will be blown off the track. The station includes an opening 48 located in the sidewall 38 `and communicating with a conventional source of pressurized nitrogen (not shown) under control of a solenoid 49 (FIG. 6) of a solenoid operated valve (not shown). The station 47 is further provided with a housing 51 located adjacent track 22 and connected to the support member 34 by any suitable means, such as a bracket 52 (FIG. 2). A photocell 53 and a light source S4 are disposed angularly with respect to each other in the housing 51 such that as a wafer passes over the opening 48 the light from source 54, which is arranged so as to irradiate the entire wafer in this position, is reflected to the photocell 53.

The amount of reflected light received by the photocell 53 is dependent upon which surface of the wafer, i.e., top or bottom, is presented to the light source, the top surface, since it is polished, reflecting more light than the bottom surface which is relatively dull. Since the resistance of the photocell 53 is inversely proportional to the amount of light incident thereon, that is, the resistance of the photocell decreases as the incident light increases, the difference between the light reflected from the upper surface of the wafer and that reflected from the bottom surface manifests itself as a difference in the photocell resistance.

To determine the resistance of photocell 53 and, hence, to determine which surface of the wafer is presented to the light source 54, the photocell is connected in the circuit of FIG. 6 as one arm of a bridge network, designated generally by the numeral 56. The arm adjacent to the photocell 53 is provided with a variable resistor 57 and the arms opposite thereto are provided with D.C. voltage sources 58 and 58 respectively. Each source is of equal magnitude, V, with the negative terminal of source 58 connected to the positive terminal of source 58' and to ground. Accordingly, a positive voltage, +V, appears at point 59 of the bridge 56 and an equal negative voltage, V, appears at a point 61 thereof. As is readily apparent, if the resistance of photocell 53 is equal to the resistance of variable resistor 57, the point 62 intermediate the resistor 57 and the photocell 53 will be at zero or ground potential. However, if the resistance of photocell 53 is greater than that of the resistor 57, a voltage of positive polarity will appear at point 62 and, conversely, if the resistance of photocell 53 is less than that of resistor 57, a voltage of negative polarity will appear at point 62.

The point 62 -is conne-cted to the base 63 of a transistor `64, the collector 66 of the transistor being connected to a suitable source of positive D.C. voltage, e.g., point 59, and the emitter 67 thereof being connected through a resistor 68 to ground and to the gate element 69 of a silicon controlled rectifier 7|1. The rectiiier 7:1, in turn, is serially connected to the nitrogen control solenoid 49. An A.C. voltage, from a source 7'2, which may be 115 volts, 60 cycles, is impressed across the rectifier 71 and solenoid 49.

`In operation, the bridge 56 is calibrated by adjusting the resistor 57 so that if a vwafer is advanced to the station 47 with its bottom surface presented to the lamp 54 a positive voltage will appear a-t point 62, and, if 'a wafer is .advanced to the 4station with its top surface presented to lamp 54, a negative voltage will appear at point 62. Thus, when a wafer is advanced with its bottom surface presen-ted to the lamp 54, a positive voltage appears at point 62 and, hence, at the base 63 of the transistor 64, resulting in the transistor being turned ON. In turn, this causes a gating signal to vbe applied -to nthe silicon controlled rectifier 71 which results in this unit being turned ON during the positive half cycle l'of the applied A.C. signal. As a consequence, energizing current is passed through the :solenoid 49. Upon jenerg-ization of the solenoid 49 a nitrogen stream is introduced through the opening 48 to blow the wafer off the track 22, whereupon it falls by gravity to the loading vdish 29. A diode 73 and a series resistor 74 are connected across the solenoid 49 to maintain a current `iow through the solenoid during the negative half cycle of the applied A.C. signal, since the rectifier 71 is turned OFF during this interval.

When a wafer is advanced to the station with its 'top surface presented to the lamp 54, a negative vvoltage appears at the base 63 of the transistor 64 which precludes `the transistor 64 and, hence, the silicon 'controlled rectier 711 from being turned ON. Thus, 'no energizing current is passed through the solenoid 49 to actuate the nitrogen stream, and the wafer 'remains on the track 22.

After surface testing, the base 39 `cornes to an labrupt end (FIG. 5) causing the remaining surface-matched wafers 20-20 to slide down the side-wall 38 'to a horizontal channel, designated ygenerally by the reference numeral 76. The channel 76 includes Ia horizontal base 77 having a width just sufficient `to accommodate a single wafer 20 and opposing equally inclined sidewalls 78478 which extend upwardly 4from the base and `terminate at respective lands 79 and 79', the .sidewall 78 Iat the point of track transition being a continuation of the sidewall 318. The height of the sidewalls 78 'and 78 is made slightly greater than the `dirnensionally correct thickness o'f a single wafer for reasons which will be discussed in greater detail hereinbelow.

Most of the surface-matched wafers 20-20, as they fall from the base 39 land =on kthe base 77 in a horizontal position with their top surface facing upwardly. However, som'e wafers, due to the manner in which they fall, may land edgewise on the base 77 and interfere with proper operation of the apparatus. Accordingly, to `rernove these wafers Afrom the track, a longitudinal slot I81 of a width larger than the thickness l'of a single wafer isv provided in the base 77. As `a result, those wafers which ride edgewise on the base fall through the slot 81 `and down a chute (not shown) which returns them to the loading dish 29. A

After falling into the channel 76, the wafers 20--20 proceed seriatim therealong to an or-ienting station, designated generally by the reference numeral 82 (FIGS. l, `8 and 9), which -as will be described in more detail hereinbelow is provided with rneans for selectively arresting .the movement of the wafers to enable wafers to be fed indi- Vidually into and out of the orienting station. As a result, there is a possi-bility tha-t the wafers 20---20` by virtue of their momentum may climb over one another and thereby upset their tops facing upwardly and `serial arrangement.

In order tto prevent this occurrence, a pair of cover plates 83-83 is provided for the channel 76 which extends f-rom a point starting with the rearward .end of the slot 81 (FIG. 5) to the entrance of the orienting station 82. Thus, since the height of the channel 76 is approximately equal to the dimensionally correct thickness of a single wafer, the cover plates 83H83 preclude the wafers from climbing over one another.

In the event wafers are not of the correct thickness i.e.,

climb over one another. To enable these jams to be easily cleared by an operator, a small gap is provided intermediate the cover plates 83-83.

kIt has been observed that when wafer-s are fed along a at horizontal track of the vibratory type at a low rate setting of the vibrator, they feed sluggishly and when they are .fed at a higher rate setting they feed erratically, resulting in a loss of control. This problem is obviated in the instant apparatus -by providing a longitudinal groove 84 in the base 77. This groove, it has been found, allows the wafers to Ibe fed rapidly without any loss o-f control. It is believed that the reason for .the foregoing lies in the relationship between the weight of a wafer 20 and its surface area'contact with the base along which it is being fed; that is, it is believed that the ratio of the weight-tsurface area contact of a wafer with the base is detergminative of the speed at which the wafer lwill be -fed for a given rate setting of the vibrator and that the higher this ratio Ithe smaller the vibrator Ifeed rate has to be in order to achieve a given wafer speed. Accordingly, by decreasing the surface area contact of a wafer with the track base 77, for example, by providing the groove `84, the weight-to-area ratio of the wafer is increased and the wafer can be fed rapidly at a relatively low vibrator rate setting :without loss of cont-rol.

Referring now to PIG. 2, the wafers, before entering the orienting station, pass over a photocell 85 disposed disposed beneath the base 77 and communicating there with through `a suitable opening 86. The function of the photocell 85 -is to deactu-ate the vibratory drive of circular feeder 21 (FIG. 12) when a predetermined number of wafers has accumulated in front of the orienting station'82 ready for feed thereto. In lthis manner, -a continuous row of wafers --20 is precluded from being formed in the channel 76 along a portion thereof which is not covered Iby the cover plates 831-83; since, if this were to occur, climbing of the wafers might result with -the attendant disadvantages previously mentioned.

The photocell 85 is connected in the circuit of FIG. 7 as one element of a voltage divider circuit 87 which includes a resistor 88 and a D C. voltage source 89. When ambient light impinges on the photocell 85, it assumes a first value of resistance resulting in an input signal of a first value being applied to a conventional time delay amplifier 91 to energize a relay 92 in the output thereof, hereinafter referred to as the accumulation control relay. A normally open contact 92a (FIG. 12) of the relay 92 is connected in the drive circuit of the circular feeder 21 and, when closed, enables actuation thereof, the contact remaining closed as long as light impinges on the photocell 85. However, when the light to the photocell 85 is blocked, the photocell assumes a second value of resistance, higher than the first, resulting in a lower amplifier input signal, which, if maintained at this value for a time interval equal to, or greater than the amplifier time delay, will cause de-energization of the relay 92 to de- Aactuate the drive of circular feeder 21. This latter condition occurs when a predetermined. number of wafers accumulate in front of orienting station 82 with a plurality thereof disposed over the photocell 85 for a time interval equal to, or greater than the amplifier time delay.

Referring now to orienting station 82, which is best illustrated in FIGS. 8 and 9, two functions are performed at the station when the wafers 2020 are presented thereto: first, the wafers 20-20 are inspected to determine whether they have any defects or flaws, those wafers which are considered defective being rejected; and seclond, the wafers 20--20 are inspected to determinetheir orientation, those wafers which are-of undesirable orientations being rotated to a desirable one.

As seen in FIG. 10, a wafer as it enters the station 82 can be in any one of four orientations, as determined by the position of its emitter contact 27. It is assumed, for purposes of illustration in the present invention, that the desired orientation of the wafer for a subsequent operation, such as lead bonding, is an orientation where the emitter contact 27 is located on the left hand side of the wafer. It is apparent, therefore, that the wafer with the designated 0 orientation in FIG. 10 is the wafer depicting the desired orientation, and that the others are of undesirable orientations and, accordingly, must be rotated clockwise by the amounts designated in FIG. 10 in order to achieve the desired orientation.

As best seen in FIG. 8, for the purpose of enabling visual inspection of the wafer, the cover plates 83-83 do not extend into the station 82, and a microscope (not shown) is provided as an optical aid.

The wafers 20-20 advance into the station 82 until the leading one thereof engages a stop member 94 which centrally locates this wafer over an orientor, designated generally by the reference numeral 96, the next sucoeeding wafer moving into registration with a vertical bore 97 in the base .77. As will be described in more detail below, during the orienting of a wafer 20 by the orientor 96, a partial vacuum (hereinafter referred to as the hold vacuum) is drawn through the bore 97 to preclude movement of the wafer located thereover.

The orientor 96, as best seen in FIG. 9, comprises a hollow tubular member 99 secured to the top of a vertically movable and horizontally rotatable shaft 101. A vertical cylindrical housing 102 for the shaft 101 is secured to the underside of the track 22 by suitable means and carries an electromagnetic coil 103 adjacent to its lower extremity, a pair of sleeve bearings 104-104 being disposed intermediate the shaft 101 and the housing 102 to enable free movement of the shaft. When energizing current is supplied to the coil 103 it coacts with an armature 106, secured to the underside of the shaft 101, to provide vertical upward movement of the orientor 96, the amount of movement being limited by the engagement of a flange 107 formed at the top of the shaft with a thrust washer 108 secured to the underside of the track 22. Upon vertical movement of the shaft 101, the tubular member 99 moves through a vertical passageway 110 to engage, seat and carry a wafer 20 in registration therewith upwardly. When the shaft 101 is in its uppermost vertical position, the wafer is in horizontal alignment with a tube 109, which projects horizontally from a block 111 seated on the land 79. The tube 109 is arranged for connection with a source of pressurized nitrogen (not shown). If it has been determined that the wafer is defective, a stream of nitrogen is introduced into the tube 109 to blow the wafer off the orientor tube 99 and into a funnel-shaped receptacle 112 located adjacent to the track 22. From the receptacle 112 the wafer is drawn by a partial vaccum to a reject container (not shown).

If the wafer is acceptable, it is secured to the free end of the orientor tube 99 during the vertical movement of the orientor 96 by means of a partial vacuum. This is accomplished by providing an opening 113 in the tube 99 adjacent to its lower end, and introducing a partial vacuum through a horizontal bore 114 to a gas tight vertical chamber 116 formed in the track 22. It should be noted that by virtue of this arrangement, a vacuum is maintained within the orientor tube 99 during Iboth its rotational and vertical movement. In order to facilitate the downward movement of the shaft 101 upon de-energization of the coil 103, a compression spring 117 is disposed in the chamber 116 with its upper end contacting the ceiling of the chamber and its lower end contacting an annular blank 118 secured to the tube 99.

Rotational motion is imparted to the shaft 101 by a motor 119 (FIG. 13) whose shaft 124 drives a flexible shaft 121 connected to the shaft 101. A cam 122 having four detent receiving means, such as lobes 123-123, equally spaced around the periphery thereof is secured to the motor shaft 124l to enable 90 incremental rotation thereof and, hence, of the shaft 101 as well. The incremental rotation is accomplished by energizing for one of three predetermined time intervals a conventional relay 126 having its armature 125 modified to include a detent 127 which, as seen, is normally engaged with the leading edge of one of the lobes 123. Upon energization of the relay 126, the armature 125 retracts, thereby retracting the detent 127 to free the motor for rotation, the motor continuing to rotate until after de-energization of the relay the detent re-engages the leading edge of a cam lobe 123. It should be noted that during each 90 rotation of the cam 122, the relay armature 125 is held in the retracted position by virtue of the engagement of the detent 127 with the peripheral surface of the cam intermediate a pair of lobes 12S- 123.

The three time intervals correspond to the time necessary for the motor to rotate through angles of 90, 180 and 270 respectively. Thus, for example, if the speed of the motor is 60 r.p.m., as in the present instance, the motor will rotate through 90 in .25 second, through 180 in .5 second and through 270 in .75 second. The three time intervals are selected accordingly, with each being slightly less than the actual time necessary to complete its corresponding rotation, as will be seen below.

The time intervals are provided by a circuit, designated generally by the numeral 128, which forms a part of FIG. 13. The circuit includes three like transistor time delay circuits 129, 131 and 132, the respective outputs of which are connected to the base 133 of an output transistor 134 having a relay 136 connected in its collector circuit. Biasing resistors 137 and 138 are connected to the emitter 139 and to a D.C. power supply 141. The base 133 of the transistor 134 is additionally connected through a resistor 142 to the positive terminal of the supply 141.

Since the operation and structure of each time delay circuit is essentially identical only one, i.e., 129, will be described in detail. The circuit 129 includes a transistor 143 having its emitter 144 connected to the negative terminal of the supply 141 and its collector 146 connected to the base 133 of the output transistor 134 and to the resistor 142. The base 147 of the transistor 143 is connected through a high value variable resistor 148 to one end of a relatively lower value fixed resistor 149 and to one end of a capacitor 151, the other end of the resistor 149 being connected through a normally open switch contact 153 to the positive tenminal of the supply 141 and the other end of the capacitor 151 being connected to the negative terminal of the supply. The switch contact 153 is controlled by a four position lever switch 152. The four positions of the switch correspond to the amount of rotation necessary to rotate the wafer to the desired orientation, i.e., 90, 180 and 270 respectively. In the position of the switch corresponding to 90, the switch contact 153 is closed; in the position of the switch corresponding to 180, the switch contact 154 is closed; and in the position of the switch corresponding to 270, the switch contact 156 is closed. The operation and function of other contacts of the switch 152 will be further described below.

In operation, if none of the contacts 153, 154 or 156 is closed, a signal is applied from the supply 141 through the resistor 142 to the base 133 of the output transistor 134 of a sufcient magnitude to turn it ON and thereby energize the relay 136. However, when one of the contacts is closed eg., contact 153 of the 90 time delay circuit 129, the capacitor 151 thereof is charged through the low value xed resistor 149 resulting in the transistor 143 being turned ON and its collector voltage and, hence, the voltage at the base 133 of the output transistor 134, dropping to a low value, i.e., a value lower than the emitter voltage of the transistor 134. This results in a turning OFF of the transistor 134 and a de-energization of the relay 136. Upon a subsequent opening of the Contact 153, the charge on the capacitor 151 flows into the base 147 and keeps the transistor 143 ON for a time interval dependent upon the value of the capacitor 151 and the setting of the variable resistor 148. For example, in the present instance the values would be selected so that a time delay of .2 second results. After discharge of the capacitor 151 the transistor 143 turns OFF resulting in the output transistor 134 being turned ON and the relay 136 being doi-energized. As will be described in more detail below, a normally closed contact 136a of the output relay 136 is in a circuit which along with the switch 152 controls the operation of the orienter control relay 126; hence, this latter relay is energized for the length of time the output relay 136 remains energized upon the closing and opening of the switch contact 153.

The operation of the 180 and 270 time delay circuits 131 and 132 respectively is similar to that of the 90 time delay circuit 129 with the exception that the values of their respective capacitors and the settings of their respective variable resistors are selected to provide time delays of .45 second and .7 second, respectively.

Referring again to FIG. 8, the stop member 94 is generally L-shaped and is pivotally movable between an upper and lower position. In the lower position the stop member 94 (as shown) functions to centrally locate a wafer 20 over the passageway 110 communicating with orientor 96, and in its upper position functions to allow a wafer 20 to move out of the station 82 after orientation thereof. The stop member 94 is secured to one end of a rod 157 which is journaled for rotation about a horizontal axis in the support block 111. The other end of the rod is connected through suitable linkages 158 and 159 to an armature 161 of a relay 162 mounted on the track support 34. Energization of the relay 162 results in rotation of the rod 157 to rotate the stop member 94 clockwise (FIG. 8) to its upper position, and de-energization of the relay causes the stop member to rotate counterclockwise to its lower position in engagement with the channel base 77.

Since the fixed cover plates 83-83 do not extend into the station 82, during the transfer of a wafer from the bore 97 into engagement with the stop member 94 a movable cover plate 163 is actuated to cover the channel 76 and thereby preclude a climbing of the wafers. The movable cover plate 163 is generally L-shaped and has one end xed to the upper end of a vertical shaft 164 journaled in track land 79 for rotation about its vertical axis. The bottom of the shaft 164 is connected through suitable linkage 166 and 167 to a plunger 168 of a solenoid 169 mounted on the track support 34. Energization of the solenoid 169 results in rotational movement of the shaft 164 to cause the cover plate 163 to move to a retracted position as shown in FIG. 8, thereby uncovering the channel '76 and allowing unobstructed viewing of the wafer; conversely, de-energization of the solenoid 169 results in the cover plate 167 covering the channel 76.

After orientation, to be described later in more detail, the oriented wafers 20-20 are fed to a removable, channeled magazine 171 (FIG. l). The channel 172 of the magazine 171 is accurately aligned with the exit end of the track channel 76 by a plurality of suitable positioning and securing means 173, 174, 175 and 176.

To determine when the magazine 171 is full and to deactuate the respective vibratory drives of the circular feeder 21 and linear track 22 accordingly, at the entrance of the magazine 171, light from a source 177 is radiated on a photocell 178 (FIG. 2) through suitable apertures and 180 in the base 77 and magazine, respectively. The photocell 178 is connected in the circuit of FIG. l1 which functions in a like manner to the circuit of FIG. 7 previously described. Thus, when the light to the photocell 178 is blocked for a predetermined time interval, which will occur when the magazine 171 is full, the output signal of the amplifier falls below the value necessary to maintainl energization of a relay 181 in the output thereof, hereinafter referred to as the full magazine relay. A normally open contact 181er (FIG. l2) of the relay 181, as will be seen shortly, is connected to the respective vibratory drive circuits of both the circular feeder and linear track, and is functional upon de-energization of the relay 181 to deactuate both drives.

It should be obvious, that instead of being fed to a magazine, the wafers after orientation can be fed directly to a subsequent processing station or machine.

Operation Referring now to FIGS. 12 and 13 (combined as shown in FIG. 1-4), there is illustrated a control circuit for the apparatus. In order to facilitate association of relays and relay contacts, relay contacts operated by a relay are designated by the relay reference number followed by an identifying letter. For example, the two relay contacts controlled by a relay 191 are designated 191e and 191i). Switch contacts are readily distinguishable from relay contacts since each switch contact `is designated by a whole number only.

Preparatory to operation, a main power switch 182 is closed to energize a pair of bus lines 183 and 184 from a suitable source of A.C. power 18S, in the instant case, 115 v., 60 cycles. This results in a relay 186 being energized through a normally closed feed button contact 187 and a normally closed contact 188a of a relay 188.

A start button contact 189 `is then momentarily depressed, thereby energizing a start relay 191 through a normally closed stop button contact 190. Energization of the start relay 191 closes its normally open contacts 191er and 191b. Since the full magazine relay 181 (FIG. l1) is normally energized, its normally open contact 181a is closed at this time; hence, upon closure of contact 191e, a holding circuit is established for the start relay 191. Closure of contact 19112 conditions respective energizing circuits for the linear vibratory drive coil 36 and the drive control solenoid 192 of the circular feeder 21, the contact 186a being open at this time by virtue of the previous energization of the relay 186, and the contact 92a being closed at this time since the accumulation control relay 92 (FIG. 7) is normally energized. Both the linear vibratory drive coil 36 and the drive control solenoid 192 are energizable through respective auto-transformers 193 and 194 and respective rectifier diodes 196 and 197, whose function is to provide pulsed D C. operation of each drive unit.

To commence operation, the feed button contact 187 is depressed to de-energize the relay 186, which closes the contact 186e: and 4thereby completes the respective energizing circuits for the linear vibratory drive coil 36 and the circular feeder drive control solenoid 192. Accordingly, wafers are fed from the circular feeder 21 to the linear track 22; formed into a single row; screened to eliminate oversize and undersize wafers, as well as particles; surface tested to remove those wafers from the track which are advanced with their top surface contacting the sidewall 38; and advanced along the horizontal channel 76. The operator maintains the feed button 187 depressed until the leading wafer is fed against the stop member 94, which is in its lower position since no energizing current is supplied to its operating relay 162 at this time. The feed button 187 is then released, resulting in the following actions: energization of the solenoid 169 to retract the movable cover plate 163 (FIG. 8) and thereby uncover the channel 76 to allow unobstructed inspection of the leading wafer; energization of a solenoid 193 of a solenoid operated valve (not shown) to actuate the hold vacuum, whereby the wafer in registration with bore 97 is restrained; energization through a normally cl-osed contact 162e of the stop relay 162 of a solenoid 194 of a solenoid operated valve (not shown), to draw a partial vacuum through lthe orientor tube 99 and thereby secure the leading Wafer thereon; and re-energization of the relay 186 to de-energize the drive coil 36 and solenoid 192 Eof the linear track 22 and circular feeder 21 respectively. The present condition of the apparatus will hereinafter be referred to as its inspection condition, -that is, the apparatus is now in a condition to enable inspection of a wafer.

Next, an operator views the. leading wafer 20 through a microscope (not shown) to determine whether the wafer is acceptable and, .if acceptable, the orientation thereof. If the wafer is unacceptable, the operator operates a reject switch 196 to close its normally open contacts 197 and 200. Closure of the contacts 197 and 200 energizes a solenoid 198 of a solenoid operated valve (not shown) to introduce a nitrogen stream through the reject tube 109 (FIG. 9) and completes a circuit to a relay 199 which closes its contacts 199a and 199b.

Closure of contact 199a energizes the relay 188, thereby effecting a closure of the contacts 188b and 188C and `an opening of` contact 188:1, the closure of contact 188b completing a holding circuit for the relay 188 through the closed feed button Contact 187, and the opening of contact 188a de-energizing relay 186 to re-energize theV drive coil 36 and solenoid 192 of the circular feeder 21 and linear track 22, respectively. The closure of contact 188e energizes the stop control relay 162 to raise the stop member 94 to its upper position, close the contact 16212 and open the contact 1612er. The opening of contact 162a deactuates the vacuum to the orientor tube 99, and the closure of contact 162b completes a circuit to the orientor lift coil 103 through the contact 197, the contact 200 and a rectifier 201. The resistor 202 and capacitor 203 associated with the rectifier form a filter for the rectified sign-al applied to the coil 103. As a result of the energization of the lift coil 103, the shaft 101 raises, whereupon the wafer is contacted by the actuated nitrogen stream and is blown off the orientor tube 99 to the receptacle 112 and, thence, to a reject container (not shown). Upon release of the reject switch 196, the relay 199 is de-energized and the circuit to the lift coil 103 is opened, resulting in a lowering of -the shaft 101. The present condition of the apparatus, which will hereinafter be referred to as the rest condition, is as follows: both drive circuits are actuated; the movable cover plate 163 is retracted; the hold vacuum is actua-ted; and the stop 94 is in its upper position by virtue of relay 188 and, hence, relay 162 remaining energized.

To feed another wafer into the station, the feed button `contact 187 is depressed, resul-ting in deactuation of the hold vacuum, movement of the movable cover plate 163 to cover the channel 76, de-energization of relay 188, and movement of the stop member 94 to lits lowered position. The feed button Contact 187 is maintained depressed until -the Wafer which had been held by the hold vacuum is fed into engagement with the lowered stop member 94. The feed button contact 187 is then released, thereby placing the apparatus in its inspection condition.

If the wafer under inspection is acceptable, the four position switch 152 is operated selectively to a position thereof which corresponds to the amount of rotation necessary to rotate the wafer to the desired orientation. Obviously, if the wafer is of the desired orientation, no rotation is required and the switch is operated to its 0 position, resulting in the closure of contact 204 and the opening of contact 206. The closure of contact 204 energizes relay 199, whereupon the same action wh-ich took place when this relay was energized in the reject situation above ensues, with the exception that the reject nitrogen stream is not actuated and the vacuum to the orientor tube 99 is continuously actuated. Accordingly, the stop member 94 moves to its upper position and the shaft 101 raises, the wafer remaining on the orientor tube 99. The continuous actuation of the oriente-r tube vacuum is achieved by virtue of a circuit being completed to the solenoid 194 through the closed 0 contact 204, the reject switch armature 196, the reject switch 13 contact 207 and the closed contact 199b. Upon release of switch 152 to its inoperative position, the lift coil 103 is de-energized to lower the shaft 101 and the apparatus is placed in its rest condition, with the Wafer under consideration being advanced to the magazine 171.

If the wafer under inspection is of an undesirable orientation, the switch 152 is operated either to its 90, 180 or 270 position and, accordingly, opens either contact 208, 209 or 211 and closes either contact 153, 154 or 156, respectively. Opening of either contact 208, 209 or 211 disables the rotary control relay 126, while closure of either contact 153, 154 or 156 selects one of the three time delay circuits 129, 131 or 132 to de-energize relay 136, as was explained above. De-energization of relay 136 closes contact 136a which, in turn, results in energization of relay 199 through the contact 136:1, the normally closed contact 126a of the rotary control relay 126, the reject switch armature 196 and the reject switch contact 207. Accordingly, -the same action which ensued upon the energization of relay 199 in the orientation example above, takes place, that is: the shaft 101 is raised; the vacuum to the orientor tube 99 is maintained actuated; and the stop member 94 is moved to its upper position. Upon release of switch 152 to its inoperative position, a circuit is completed to the rotary control relay 126, the contact 136a, a-s explained above, remaining closed for a time interval dependent upon which time delay circuit was selected. Energization of relayV 126 closes contacts 126b and 126e and opens contact 126a. Closure of contact 126b maintains the energization of those circuits which were previously energized lthrough contact 126a, and closure of con-tact 126C energizes the motor 119 which is free to rotate since the cam -122 is disengaged upon the energization of relay 126..

Accordingly, rotary motion is imparted to the shaft 101. Upon expiration of the selected ltime delay circuit time interval, the relay 136 re-energizes thereby opening the contact 136:1 and de-energizing the rotary control relay 126; however, due to the engagement of the relay detent 127 with the cam peripheral surface intermediate a pair of lobes 123, the contacts 126b and 126C remain closed. The shaft 101 continues to rotate for a short time until the detent 127 engages a cam lobe 123 thereby arresting the motion of the motor shaft 124 and opening the contacts 126b and 126e. Opening of contact 126C de-energizes the motor 119, while opening of contact 126b deenergizes the lift coil 103 causing the shaft to lower, and places the apparatus in its rest condition, the oriented wafer being advanced to the magazine 171.

It is to be understood that the above-described arrangements are simply illustrative of the applic-,ation of the principles of the invention. Numerous other arr-angements may be devised by those skilled in the art which `will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. Apparatus for feeding and orienting initially, randomly disposed articles to position the articles in a predetermined orientation, each article having first and second Surfaces of different light reflectivity characteristics, said first surface additionally having a marking thereon, which comprises:

means for receiving :such articles and advancing the same along a predetermined path of travel;

light sensing means including a light source and a photoelectric device positioned adjacent to said path for inspecting a surface of each of the articles exposed thereto and for sensing the light reflectivity characteristics of the exposed surface;

said article-receiving and advancing means including a track and Vibratory means coacting with said track for imparting linear movement to the articles to advance the same along the track, said track having an inclined sidewall with an opening therein and an adjoining base portion projecting laterally from the bottom of the sidewall arranged so that articles advance along the track with one of the surfaces of each article contacting the inclined sidewall and an edge of the article supported on the base portion, said base portion along at least a section thereof having a width sufficient to support only a single article so as to preclude an article from traveling with one of the surfaces thereof superimposed on the surface of another article, said sidewall opening being larger than the surface area of a single article and being positioned in the sidewall at a height above the base approximately equal to the edge length of the articles so that any article riding on top of another article falls through the opening, whereby the advancing articles are arranged seriatim for presentation to the light sensing means; means communicating with said opening for returning articles entering said opening to the track for refeeding; v

means responsive to said light :sensing means for distinguishing the light reflectivity characteristics of said first surface from those of said second surface and for ejecting from the series of advancing articles each of the articles which lhas been presented to the light sensing means with the second surface thereof exposed for inspection, whereby each of the remaining articles of the advancing series has the first surface thereof facing in a common direction; and

means disposed in the path of travel of the remaining surface-matched articles advancing along said track and operable for selectively engaging and rotating an individual article to position the article so that each article has the surface marking thereof facing in a common direction. 2. Apparatus for feeding, sizing and orienting randomly disposed generally square wafer-like articles to position those articles of an acceptable size in a predetermined orientation, each article having opposed first and second surfaces of different light reflectivity characteristics, which comprises:

an article feeding track of the vibratory type including an inclined sidewall having first, second, third and fourth openings therein and a base extending therefrom, the configuration of the base along a section thereof and the inclination of the sidewall causing articles to travel along the track with one of their surfaces contacting the sidewall, said first opening being adapted to remove all articles from the track other than those which are base contacting, said second opening being adapted for passage therethrough of a stream of fluid to remove all articles greater than a desired size from the track, and said third opening being adapted to remove all articles less than a desired size from the track, whereby a single row of substantially dimensionally correct articles is formed for presentation to said fourth opening;

light sensing means positioned adjacent to the track at the fourth opening for inspecting a surface of each of the articles exposed thereto and for sensing the light reflectively characteristics of the exposed surface;

means responsive to said light sensing means for distinguishing the light reflectivity characteristic of said first surface from those of said second surface and for introducing a stream of fluid into the track through said fourth opening to eject from the series of advancing articles each of the articles which has been presented to the light sensing means with the second surface thereof exposed for inspection, whereby each of the remaining articles of the advancing series has the first surface thereof facing in a common direction; and

means disposed in the path of travel of the remaining surface-matched articles advancing along said track and operable for selectively enga-ging and rotating an individual article to position the article in a desired angular orientation in the plane of said first surface. 3. Apparatus for feeding and orienting .randomly disposed articles to position the articles in a predetermined orientation, each article having a marking on a first surface thereof, which comprises:

means for receiving such articles, arranging them so that their first surfaces are facing in a common direction and advancing the arranged articles along a predetermined path of travel; and

means disposed along the path of travel of the arranged articles for selectively engaging and rotating an individual article to position said article in a desired angular orientation in the plane of said first surface, said engaging and rotating means including rotatable means movable between a first location and a second location, in said first location said rotatable means being out of engagement with said article and in said second location said rotatable means being in engagement with and holding said article, means for moving said rotatable means between said first and second locations, means for imparting rotary movement to said rotatable means, means engageable with the rotary imparting means for controlling the movement thereof, a plurality of selectively actuable time delay circuits, the time delay of each circuit corresponding to the time required for the rotary imparting means to rotate through a particular angle, and means responsive to the actuating of any one of the time delay circuits for operating the controlling means for a time interval dependent upon the selected time delay circuit. 4. Apparatus in accordance with claim 3, wherein the receiving, arranging and advancing means includes:

a first vibratory track for receiving the randomly disposed articles and arranging them seriatim;

sensing means positioned adjacent to the first track for inspecting a surface of each of the seriatim arranged articles;

means responsive to the sensing means for ejecting each Iarticle from the first track which does not have a surface marking on the surface thereof inspected by the sensing means, whereby each of the remaining articles has the surface thereof with the surface marking facing in the same direction; and

a second vibratory track for receiving the remaining articles from the first track and advancing the same to the engaging and rotating means.

5. Apparatus in accordance with claim 4, wherein the first track includes an inclined sidewall and an adjoining base portion projecting laterally from the bottom of the sidewall arranged so that articles advance along the track with one of the surfaces of each article contacting the inclined sidewall and an edge of the article supported on the base portion, said base portion along at least a section thereof having a wid-th sufficient to support only a single article so -as to preclude an article from traveling with one of lthe surfaces thereof superimposed on the surface of another article and said sidewall along at least a section thereof having a slant height sufiicient to support only a single article so as to preclude an article from traveling with one of its edges supported upon an edge of another article, whereby the advancing articles are arranged seriatim for presentation to the sensing means.

6. Apparatus in accordance with claim 5, wherein the first track sidewall has a first opening along its length at a height above the base just greater than the maximum desired edge length of an article;

means are provided for `propelling a stream of pressurized fluid through the first opening to eject any oversize articles from the track;

the first track sidewall has a second opening along its length extending to the lbase and just smaller than the minimum surface area of an article so that undersize articles fall off the track,

7. `Apparatus in accordance with claim 4, wherein said second track includes a substantially horizontal base having a longitudinal groove extending therethrough in the direction of travel of articles being advanced along said base to cause said articles to travel along said base relatively rapidly and in a controlled manner.

8. Apparatus in accordance with claim 7, further including:

means selectively operable for feeding articles individually to and from the engaging and rotating means; and

means operable in timed relationship with said individual feeding means for locating an article received from said individual feeding means in registration with the engaging and rotating means and for enabling said article to be moved out of registration with said engaging and rotating means after positioning thereof.

9. Apparatus in accordance with claim 8, further including:

means fixedly associated with said second track for covering a portion of the second base to preclude articles from climbing over one another along said second base; and

movable means operable in timed relationship with said individual feeding means and said locating means for covering said second base intermediate said fixed covering means and said locating means when an article is being advanced from said individual feeding means to said locating means.

10. Apparatus for collocating randomly disposed, generally square, wafer-like articles into a single row of substantially dimensionally correct articles which comprises:

a track having an inclined sidewall and an adjoining base portion projecting laterally from -the bottom of the sidewall arranged so that articles are caused to travel along the track with `a surface thereof contacting the inclined sidewall and an edge of the article supported on the base portion, said base portion along at least a section thereof having a width sufficient to support only a single article so as to preclude Lan article from traveling with one of the surfaces thereof superimposed on the surface of another article, said sidewall along at least a first section thereof having a slant height sufficient to support only a single article so as to preclude an article from traveling with one of its edges supported upon an edge of another article;

the sidewall having a first opening along its length at a height above Ithe base just greater than the maximum desired edge length of an acceptable article; means for propelling a stream of pressurized fluid through the first opening to eject any oversize articles `from the track;

the sidewall having a second opening along its length extending to the base and just smaller than the minimum surface area of an acceptable article so that undersize articles fall off the track; and

vibratory 4means coacting with said track for imparting linear movement to the articles to advance the same along the track whereby the articles are collocated into a single row `of substantially dimensionally correct articles.

11. Apparatus in accordance with claim 10 for orienting the articles after collocating, each of the articles having opposed surfaces of different reflectivities, which apparatus further includes:

light sensing means positioned adjacent to the track for sensing the light reflectivity of the exposed surface of each article; and

means responsive to the light-sensing means, for ejecting from the advancing row of articles all those which do not have a desired one of the surfaces exposed so that, thereafter, all remaining articles in the row have the desired surface exposed.

17 1`2. Apparatus in accordance with claim 11, further including:

means disposed in the path of travel of the remaining surfaced-matched -articles for selectively engaging land rotating an individual article to position the article in a desired angular orientation in the plane of the desired surface.

References Cited by the Examiner UNITED STATES PATENTS 2,028,917 1/1936 Owen 214-1 2,417,878 3/ 1947 Luzietti 209-73 X 2,584,327 2/1952 Capst-ack 209-1117 2,615,567 10/ 1952 Campbell 209-73 2,652,139 9/1953 Baehr 198-33.2 2,845,177 7/ 1958 Perkins 209-1117 2/1960 Johnson 74-822 10/ 1960 Denver 74-822 12/1960 Spurlin 209-83 X 9/ 1961 Campbell 209-73 7/ 1962 Phil'bin `209--82 9/1963 Booth 214-1 12/ 1963 Eleftheron 198--33.2

6/ 1964 4Arnold 209-85 X FOREIGN PATENTS 1/ 1958 Italy.

Examiners. 

1. APPARATUS FOR FEEDING AND ORIENTING INITIALLY, RANDOMLY DISPOSED ARTICLES TO POSITION THE ARTICLES IN A PREDETERMINED ORIENTATION, EACH ARTICLE HAVING FIRST AND SECOND SURFACES OF DIFFERENT LIGHT REFLECTIVITY CHARACTERISTICS, SAID FIRST SURFACE ADDITIONALLY HAVING A MARKING THEREON, WHICH COMPRISES: MEANS FOR RECEIVING SUCH ARTICLES AND ADVANCING THE SAME ALONG A PREDETERMINED PATH OF TRAVEL LIGHT SENSING MEANS INCLUDING A LIGHT SOURCE AND A PHOTOELECTRIC DEVICE POSITIONED ADJACENT TO SAID PATH FOR INSPECTING A SURFACE OF EACH OF THE ARTICLES EXPOSED THERETO AND FOR SENSING THE LIGHT REFLECTIVITY CHARACTERISTICS OF THE EXPOSED SURFACE; SAID ARTICLE-RECEIVING AND ADVANCING MEANS INCLUDING A TRACK AND VIBRATORY MEANS COACTING WITH SAID TRACK FOR IMPARTING LINEAR MOVEMNET TO THE ARTICLES TO ADVANCE THE SAME ALONG THE TRACK, SAID TRACK HAVING AN INCLINED SIDEWALL WITH AN OPENING THEREIN AND AN ADJOINING BASE PORTION PROJECTING LATERALLY FROM THE BOTTOM OF THE SIDEWALL ARRANGED SO THAT ARTICLES ADVANCE ALONG THE TRACK WITH ONE OF THE SURFACES OF EACH ARTICLE CONTACTING THE INCLINED SIDEWALL AND AN EDGE OF THE ARTICLE SUPPORTED ON THE BASE PORTION, SAID BASE PORTION ALONG AT LEAST A SECTION THEREOF HAVING A WIDTH SUFFICIENT TO SUPPORT ONLY A SINGLE ARTICLE SO AS TO PRECLUDE AN ARTICLE FROM TRAVELING WITH ONE OF THE SURFACES THEREOF SUPERIMPOSED ON THE SURFACE OF ANOTHER ARTICLE, SAID SIDEWALL OPENING BEING LARGER THAN THE SURFACE AREA OF A SINGLE ARTICLE AND BEING POSITIONED IN THE SIDEWALL AT A HEIGHT ABOVE THE BASE APPROXIMATELY EQUAL TO THE EDGE LENGTH OF THE ARTICLES SO THAT ANY ARTICLE RIDING ON TOP OF ANOTHER ARTICLE FALLS THROUGH THE OPENING, WHEREBY THE ADVANCING 